Effect of Magnetic Field Intensity and Exposure Time on the Mycelial Growth of Pleurotus ostreatus and Pleurotus pulmonarius

The effect of 4 different degrees of magnetic fields (2 mT, 25 mT, 50 mT and 100 mT) and 3 different exposure times (5, 15, 30 minutes) on the mycelial growth of two species of oyster mushroom (Pleurotus ostreatus and P. pulmonarius) were investigated in this study. The Potato Dextrose Agar (PDA) was used for the cultivation of these two mushroom species. PDA was sterilized in autoclave for half an hour at 121 C and then poured into the petri dishes at a rate of approximately 30 ml per dish. The dishes were vaccinated with mycelium of fungi that loaded on wheat grain. One grain of wheat was placed in the center of each petri dish and then an adhesive parafilm tape was placed around the edge of each petri dish to prevent contamination. The experiment was carried out in sterile conditions with five replicates per treatment and a total of 130 dishes. The average diameter of the fungal colony was measured every two days for a period of 20 days to determine the effect of magnetic field intensity and exposure time on the mycelial growth. The results indicated that mycelial growth of P. ostreatus and P. pulmonarius was influenced by magnetic field intensity and interaction of two factors (magnetic field intensity X exposure time). The magnetic field exposure of 100 mT for 30 minutes promoted the mycelial growth of both mushrooms significantly. On the other hand, the slowest growth of the P. ostreatus and P. pulmonarius mycelium was observed at 2 mT x 30 minutes and 50 mT x 5 minutes, respectively.